"This is going to put kids in police cars that have never been in trouble before," Watkins said. "They're going to be angry, they're going to feel violated. The positives that can come out of the curfew can't outdo the negatives."

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Current law requires kids up to 14 to be off the streets between midnight and 5 a.m. every day. The revision would impose an 11 p.m. to 5 a.m. weekday curfew on juveniles 17 and younger unless they had an acceptable reason to be out.

On Friday and Saturday nights, the curfew would extend until midnight. Violators would be taken to the Hamilton Recreation Center in the Fillmore and held until their parents picked them up.

Supervisors are set to consider the proposal at their July 31 meeting. If the curfew is voted down, as opponent Angela Alioto said she expects, the mayor has vowed to seek a public vote.